How to set SMS reminder when iphone is turned off and turned on?

The SMS reminder method after the machine is turned on is very simple:

1, mobile company's SMS reminder service after the machine is turned on;

2. Call the other party and it will be turned off. Then when the other party turns on the phone, you will receive a message telling you that the other party's phone is currently in a normal call state, so that you can know whether the other party is turned on.